Petra is definitely the ringleader. The other evening, before the foursome they were in the living room near the table. All four were doing a sort of group hug. Tanya was face to face with Akira and making out. Petra looked at Akira and twirled her finger to turn Tanya around. Akira immediately complied and had a knowing look on his face as if this was a part of a plan they had discussed earlier.
Petra then proceeded to go down on Tanya, or up to be more precise. I don't know if all is scripted here but it does look like the porn trio at least plot. It is clear that Petra is the boss in Apt 2 and may be acting under general instruction from VV.
As far as Ivorian and Petra, I am sure he reported back to her "mission accomplished." This site has taken a sick turn. If Dizi and Ivorian become a couple, who will Petra have to fk? The new guy?